Rotational, translational and torqueing control members for an endoscopic instrument

ABSTRACT

A flexible endoscopic dip applier includes a flexible coil with a manual actuator coupled to one end and a jaw assembly coupled to the other end. A store of clips is arranged adjacent to the jaw assembly and a clip pusher is arranged adjacent to the store of clips. The actuator includes a lever for opening and closing the jaws, a knob for rotating the jaw assembly, and a crank for dispensing clips. The knob and the lever are coupled to a single control member which extends through the coil to a joiner where it is joined to a pair of pull wires coupled to the jaws. The crank is coupled to a second control member which is threaded along a distal portion. The threaded portion engages a threaded member near the pusher and is coupled to the pusher such that rotation of the threaded control member by the crank causes the pusher to be moved distally.

This application is related to U.S. Ser. No. 10/867,412 entitled“SURGICAL CLIP”, filed on an even date herewith, the complete disclosureof which is hereby incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates broadly to surgical instruments. Particularly,this invention relates to flexible endoscopic instruments for usethrough an endoscope. More particularly, this invention relates to asurgical clip applier which is adapted for use through an endoscope andmay be used to clamp and/or suture, ducts, vessels, and other tissues,to anchor a tissue, or to attach a foreign body to a tissue.

2. State of the Art

Surgical clips are generally used to apply clamping force to ducts,vessels, and other tissues. In addition, surgical clips are particularlyuseful in controlling bleeding of a tissue in lieu of suturing orstapling where suturing or stapling is difficult.

Surgical clips are typically applied to tissue by clip appliers. All ofthe currently available surgical multi-firing clip appliers aresubstantially rigid devices intended to extend through a trocar port orthrough an incision to a surgical site requiring application of a clip.The devices have been rigid because a stiff pushing element has beenrequired in order to exert the required pushing force to move the clipover the tissue.

There is a substantial need for a flexible clip applier, particularlyone insertable through a lumen of an endoscope. The ability to applyclips through an endoscope would permit myriad minimally invasivesurgical solutions to medical problems, especially those of thegastrointestinal tract. However, it is accepted theory that thetransmitted force required to advance or form a clip over tissue cannotbe produced in the distal end of a long flexible device that is commonlyconstructed with a metal tubular coil, or polymer tube, such as anendoscopic device or catheter.

Generally a flexible endoscopic device (e.g., a biopsy forceps device)includes an outer tubular member, typically being constructed of a metaltubular coil or a polymer tube which is poor in transmitting forces thatimpart tensile stresses to the outer tubular member, a control elementlongitudinally movable relative to the tubular member, an end effectorcoupled to the distal ends of both the tubular member and the controlelement such that relative movement of the control element and thetubular member causes operation of the end effector, and a handle whichmoves the control element relative to the handle. This type of flexibleendoscopic instrument is limited in the amount of pushing force it cangenerate for several reasons. First, compression of a flexible controlelement (pushing element) tends to cause the pushing element to bucklewithin the outer flexible sheath of the device. If a relatively largerdiameter flexible pushing element is used such that it better resistsbuckling, the pushing element may impart too much stiffness to permit itto flex as it bends with the endoscopic instrument. Second, a flexiblepushing element of larger diameter is subject to greater frictionalforces within the outer sheath, which reduces the force transmitted fromthe handle to the end effector. If the flexible pushing element is maderelatively smaller in diameter, it is subject to kinking, which willresult in little to no force being transmitted to the distal end.Kinking is especially a problem in endoscopic instruments, because theendoscope and its lumen may be extended through a tortuous path. Formost flexible devices, especially metal coils, the outer sheath beginsto stretch when force is applied to the pushing element. This reduces oreliminates the force and relative movement of the pushing element. Forthese reasons and others, mechanical application of a relatively largedistal end pushing force, and particularly clip application, have beenabsent from the capability of flexible endoscopic tools.

In addition, it is important that the tissue about which a clip is to beapplied be substantially compressed. While the jaws apply a clampingforce which compresses the tissue, large clamping forces are difficultto achieve because of the dimensions of the relatively small jawassembly. That is, the dimensions are such that the lever arm between apivot of the jaw assembly and each jaw tang is relatively short,limiting the mechanical leverage of the jaw assembly.

Our previous application Ser. No. 10/396,962, which is herebyincorporated by reference herein in its entirety, discloses a flexibleclip applier that includes a ratchet mechanism adapted to locate a clippusher to a known location after deployment of a clip. In addition, theclip applier includes a flexible housing into which a train of clips maybe chambered. The flexible housing does not elongate when subject totensile forces. In addition, the jaw assembly is adapted to haverelatively high mechanical leverage which facilitates tissue compressionprior to application of a clip.

Since the development of the clip applier disclosed in Ser. No.10/396,962, we have developed an improved flexible endoscopic clipapplier which is the subject of the instant application.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a flexibleendoscopic clip applier.

It is also an object of the invention to provide a flexible endoscopicclip applier capable of dispensing multiple clips.

It is another object of the invention to provide a flexible endoscopicclip applier which limits the amount of force which can be applied tothe jaws of the device.

It is still another object of the invention to provide a flexibleendoscopic clip applier which limits the amount of force which can beapplied to the jaws of the device while adjusting for relative changesin the length of the outer sheath due to tortuosity of the path of theendoscope.

It is a further object of the invention to provide a flexible endoscopicclip applier which has two jaws which are rotatable about different axesto improve the mechanical advantage of the jaws.

It is also an object of the invention to provide a flexible endoscopicclip applier which dispenses clips via smooth movement of a manualactuator.

It is an additional object of the invention to provide a flexibleendoscopic clip applier which has an actuator that dispenses clipsprecisely one at a time.

Another object of the invention is to provide a flexible endoscopic clipapplier which uses a single control wire to open and close jaws as wellas to rotate them about the longitudinal axis.

A further object of the invention is to provide a flexible endoscopicclip applier having improved jaws.

An additional object of the invention is to provide a flexibleendoscopic clip applier which prevents the accidental dispensing of thepenultimate clip when the device is moved away from the ultimate clipafter it is applied.

It is yet another object of the invention to provide a flexibleendoscopic clip applier which forms clips as they are dispensed.

It is even another object of the invention to provide a flexibleendoscopic clip applier having a handle having a resistance force whichis substantially constant during a cycle of forming and applying a clip.

Yet another object of the invention is to provide a clip applier withclip-forming jaws which indicate a tissue fixation point for the appliedclip.

Even another object of the invention is to provide a clip applier with amechanism which stably advances clips through a coil and into an endeffector.

A further object of the invention is to provide an endoscopic clipapplier which can fire a clip only when the jaws of the applier areclosed.

Another object of the invention is to provide an endoscopic clip applierwhich can fire only one clip at a time, i.e. between closing and openingthe jaws.

An additional object of the invention is to provide an endoscopic clipapplier which provides a visual indication to the practitioner of thenumber of clips which are left in the applier.

Still another object of the invention is to provide an endoscopic clipapplier which stops operating after all of the clips have beendispensed.

In accord with these objects, which will be discussed in detail below, aflexible endoscopic clip applier according to the invention has arelatively long flexible coil (or tube) having a proximal end and adistal end. As used herein, the term proximal end means the end closestto the practitioner and the term distal means the end closest to thepatient. A manual actuator is coupled to the proximal end of the coiland a pair of jaws is coupled to the distal end of the coil. A store ofclips is disposed inside the coil adjacent to the jaws. The interiors ofthe jaws form anvils for bending a clip as it is pushed from the storeinto the closed jaws. The manual actuator has three controls: a leverfor opening and closing the jaws, a knob for rotating the jaws (and adistal portion of the coil) about the longitudinal axis of the coil, anda crank for dispensing a clip. The lever and knob are coupled to asingle first control member which extends through the coil to a pointproximal of the store of clips. The crank is coupled to a second controlmember which extends through the coil up to a point adjacent to thestore of clips and is threaded along a distal portion thereof.

According to the presently preferred embodiment, the lever is coupled toa force limiter which prevents too much force from being applied to thejaws when closing them. The force limiter also effectively adjusts forthe relative changes in the length of the outer sheath with respect tothe jaw control member. The knob is coupled to the first control membervia a spline coupling. The crank is coupled to the second control membervia a transmission and an energy storage device, e.g. a flywheel.

The first control member terminates proximal of the store of clips andis coupled to a joiner which is coupled to a pair of pull wires. Thepull wires extend on opposite sides of the store of clips, each beingcoupled to one of the jaws.

According to the invention, the coil is bifurcated proximal of the storeof clips and the two portions of the coil are joined by a rigid memberhaving four bores, one of which is threaded. The rigid member isdisposed distal of the joiner and the first control member extends intoone of the bores of the rigid member. In this way, rotation of the firstcontrol member causes the rigid member to rotate which causes the distalportion of the coil and the jaws to rotate about the longitudinal axis.This helps orient the jaws properly before closing the jaws on a tissueto be clipped. The two pull wires extend through two other bores in therigid member and the threaded portion of the second control memberthreadably engages the threaded bore of the rigid member. In this way,when the threaded control member is rotated (by the crank), it istranslated distally. The distal end of the threaded control member iscoupled to a clip pusher. The clip pusher is arranged adjacent to theproximally closest clip in the store of clips which are axially arrangedone after the other. When the threaded control member is translateddistally, the store of clips is moved distally until the ultimate clip(the one at the distal end of the store) enters the closed jaws and isapplied to tissue through the bending of its ends by the interior anvilsof the jaws.

The transmission and the pitch of the threads on the threaded portion ofthe second control member are arranged such that exactly one rotation ofthe crank causes exactly one clip to be dispensed. The crank ispreferably provided with a detent lock which must be engaged to releasethe crank and which automatically stops the crank after one rotation.

Further according to the invention, the jaws are identicalhermaphroditic jaws which are respectively rotatably coupled on offsetaxes to a clevis at the distal end of the distal coil. Each jaw has adistal tooth and a proximal tang. The tang is coupled to one of the pullwires and lies on one side of the longitudinal axis. The distal tooth ofthat jaw lies on the opposite side of the longitudinal axis, whichprevents side-to-side misalignment of the jaws when they are closed.

The store of clips is housed in a “garage” which is coupled to theclevis and extends proximally therefrom. The garage is a substantiallyrigid rectilinear structure which keeps the clips properly aligned andallows them to be smoothly pushed out of the garage into the closedjaws. The distal portion of the garage is provided with a pair of biasedstops which prevent the penultimate clip from moving out of the garagewhen the applier is moved away from the ultimate clip after it has beenapplied. In an alternate embodiment, the stops are made part of theclevis rather than the garage.

According to presently preferred embodiments, the crank is located onboth sides of the manual actuator to accommodate left hand and righthand use. A counter mechanism is coupled to the crank and indicates thenumber of clips remaining in the garage. The detent lock is engagable bythe lever so that the crank can only be operated when the jaws areclosed. The crank is also provided with a ratchet mechanism so that itcan only be rotated in one direction. The counter also includes a stopwhich prevents the crank from being rotated after all of the clips havebeen dispensed.

Additional objects and advantages of the invention will become apparentto those skilled in the art upon reference to the detailed descriptiontaken in conjunction with the provided figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially disassembled side elevation view of a surgicalclip applier according to the invention, shown with the lever and thejaws in an open position;

FIG. 2 is a partially disassembled perspective view of the manualactuator shown with the lever in the open position;

FIG. 3 is a longitudinal sectional view of the manual actuator shownwith the lever in the open position;

FIG. 3A is a view similar to FIG. 3 but showing the force absorbingspring in a compressed state;

FIG. 4 is a longitudinal sectional view of the manual actuator shownwith the lever in the closed position;

FIG. 4A is a view similar to FIG. 4 showing the force absorbing springin a compressed state;

FIG. 4B is a schematic view of a first alternate force absorberarrangement;

FIG. 5 is a perspective view of the manual actuator showing the crank;

FIG. 6 is a sectional view through the crank illustrating the lockingdetent;

FIG. 7 is a broken partially disassembled view illustrating the coils,the jaws, and the distal end of the manual actuator;

FIG. 8 is a broken partially transparent perspective view of the controlmembers, the joiner, the rigid member, one of the pull wires, thepusher, a portion of the garage and a portion of a clip;

FIG. 9 is a plan view of the rigid member;

FIG. 10 is a plan view of the joiner;

FIG. 11 is a broken partially transparent perspective view of thethreaded control member, the pusher, a portion of a clip, and one of thepull wires;

FIG. 12 is a perspective view of the pusher;

FIG. 13 is a partially cut away perspective view of the garage, theclevis, the jaws and a clip in the applied configuration;

FIG. 14 is a perspective view of the garage;

FIG. 15 is an enlarged broken perspective view of the distal end of thegarage illustrating the biased stops;

FIG. 16 is a broken plan view illustrating the clevis and portions ofthe jaws, pull wires, garage, and clips;

FIG. 17 is a broken partially transparent perspective view illustratingthe clevis and portions of the jaws, pull wires, garage, and clips;

FIG. 18 is a broken perspective view of the clevis, open jaws andportions of a pull wire and garage;

FIG. 19 is a distal end view looking into the open jaws;

FIG. 20 is a broken side elevational view of the clevis, closed jaws,and an applied clip;

FIG. 21 is a perspective end view of the closed jaws, clevis, and thegarage;

FIG. 22 is a broken longitudinal section illustrating the jaws closed,the clevis and a distal portion of the garage, with no clips;

FIG. 23 is a view similar to FIG. 22 but with three clips;

FIG. 24 is a plan view of the interior of a jaw;

FIG. 25 is a perspective view of the interior of a jaw;

FIG. 26 is a side elevational view of the clevis;

FIG. 27 is a distal end view of the clevis;

FIG. 28 is a schematic side elevation view in partial section of analternate embodiment of “self-pushing” threaded clips coupled to athreaded control member;

FIG. 28 a is a longitudinal sectional view of a self-pushing clip;

FIG. 28 b is an end view of the clip of FIG. 28 a;

FIG. 29 is a perspective view of a shepard's crook;

FIG. 30 is a proximal end view of a presently preferred embodiment ofthe manual actuator;

FIG. 31 is a side elevation view of the presently preferred embodimentof the manual actuator;

FIG. 32 is an exploded perspective view of the presently preferredembodiment of the manual actuator;

FIG. 33 is a view similar to FIG. 31 with the crank transparent toillustrate the ratchet mechanism;

FIG. 34 is an enlarged view of the transmission and counter gears;

FIG. 35 is a view similar to FIG. 34 with the transmission gears removedshowing the connection between the crank shaft and the counter gear;

FIG. 36 is an exploded perspective view of the presently preferredembodiment of the manual actuator showing the detent lock engagable bythe lever;

FIG. 37 is an enlarged view of the lock mechanism of FIG. 36;

FIG. 38 is a partially disassembled perspective view of a manualactuator having an alternate embodiment of a force limiting springassembly using a shuttle element;

FIG. 39 is a broken enlarged view of the spring assembly of FIG. 38;

FIG. 40 is an enlarged perspective view of an hermaphroditic part usedto form the shuttle element;

FIG. 41 is a view similar to FIG. 38 showing an alternate embodiment ofa force limiting device in the form of a spring-hinged lever;

FIG. 42 is a perspective view of the spring-hinged lever;

FIG. 43 is an enlarged perspective view of an hermaphroditic part usedto form a ball joint coupling between the control member and thespring-hinged lever;

FIG. 44 is a view similar to FIG. 20 but of an alternate jaw embodiment;and

FIG. 45 is a view similar to FIG. 18 but of the alternate jaw embodimentof FIG. 44.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to FIG. 1, a flexible endoscopic clip applier 10 accordingto the invention has a relatively long flexible coil (or tube) 12 havinga proximal end 14 and a distal end 16. As used herein, the term“proximal” means closest to the practitioner and the term “distal” meansclosest to the patient. A manual actuator 18 is coupled to the proximalend 14 of the coil 12 and a pair of jaws 20 is coupled to the distal end16 of the coil 12. The coil is preferably a flat wire coil having afriction reducing outer sheath (not shown). The invention will bedescribed in detail referring to each of its major components startingat the proximal end and working toward the distal end.

The Manual Actuator

A first embodiment of a manual actuator is shown in FIGS. 1-6. Apresently preferred embodiment of the manual actuator is shown in FIGS.30-37 and described in detail below.

The manual actuator 18 of FIGS. 1-6 has three controls: a lever 22 foropening and closing the jaws 20, a knob 24 for rotating the jaws 20 (anda distal portion of the coil 12) about the longitudinal axis of thecoil, and a crank 26 for dispensing a clip. It will be appreciated thatthe manual actuator 18 has a generally pistol shape which is similar toother endoscopic actuators. A finger grip 28 is provided opposite thelever 22 which has a thumb grip 30. Engaging hooks 32, 34 on the leverand the finger grip allow the lever to be locked as shown in FIG. 4.Those skilled in the art will further appreciate that the generaloperation of the clip applier 10 involves closing the jaws (optionallyby locking the lever 22), delivering the jaws 20 through the lumen of anendoscope to the surgical site, opening the jaws as shown in FIG. 1,positioning the jaws 20 through movement of the coil 12 and rotation ofthe knob 24 so that tissue to be clipped is located between the jaws,locking the lever 22 to close the jaws on the tissue, turning the crank26 to apply a clip, and then releasing the jaws from the clip andtissue.

Turning now to the details of the manual actuator 18 and with continuedreference to FIGS. 1-6, and FIG. 3 in particular, the lever 22 and theknob 24 are coupled to a single first control member 36. The lever 22 isrotatable about axle 23 and coupled to the control member 36 via a forcelimiting mechanism 37. The force limiting mechanism includes spring 38,a proximal coupler 38 a, a force limiter cap 38 b, a force limiting cup38 c, an overload nut 38 d, a distal coupler 38 e, and an overload shaft38 f. The overload shaft 38 f is coupled to overload nut 38 d andextends inside the spring 38 and partially into the force limiting cup38 c.

The lever 22 is coupled to the distal end of the spring 38 by a linkage44 seen best in FIG. 2. In particular, the linkage 44 includes aU-shaped member 44 a which fits over the spring 38 and its associatedelements 38 a-38 f. A pin 44 b couples the proximal end of the U-shapedmember 44 a to a slot 22 a in the upper part of the lever 22 and asecond pin 44 c couples the distal end of the U-shaped member 44 a tothe overload nut 38 d.

With the provided arrangement, movement of the lever 22 towards thefinger grip 28 causes the linkage 44 to move proximally which moves theoverload nut 38 d proximally. The overload nut 38 d in turn pushesagainst the spring 38 moving it proximally. The spring 38 pushes againstthe cup 38 c which presses against the limiter cap 38 b which in turnpresses against the proximal coupling 38 a. Since the proximal coupling38 a is affixed to the control member 36, proximal movement of theproximal coupling 38 a causes proximal movement of the control member36. Effectively, then, the entire force limiting assembly 37 is movingproximally and pulls the control member 36 proximally.

If at any time during the closing of the jaws the tension on the controlmember 36 exceeds a predetermined force limit of the spring 38 (e.g.,seventeen pounds), the spring force of the spring 38 will be overcomesuch that the spring 38 will compress and the overload shaft 38 f andthe overload nut 38 d will move away from the distal coupler 38 ewithout moving the control member 36 as seen in FIG. 3A. In this forceoverload situation, the shaft 38 f is received into the hollow 38 c′ ofthe force limiting cup 38 c.

FIG. 3A shows the force limiting spring 38 in the compressed positionduring closing of the jaws. This will occur when the control member 36is pulled beyond the distance normally necessary to close the jaws (e.g.when the jaws are prevented from closing all the way because they aresurrounding a very thick or very hard tissue, or if the tortuosity ofthe path of the coil causes an effective lengthening of the coil,effective shortening of the control member 36, thereby increasing thestroke of the lever 22, shortening the stroke required to close thejaws). The spring 38 prevents the jaws, the tissue and/or the controlmember 36 from being damaged due to excessive loads while allowing thelever 22 to be fully actuated to the latched position.

If, after the lever 22 has moved to a position as shown in FIG. 4 wherethe jaws have been closed, excessive force is applied to the controlmember 36 (e.g., while delivering the jaws to the surgical site througha tortuous endoscopic path), the force limiting mechanisms 37 will alsooperate to prevent damage to the control member 36. In particular, asseen in FIG. 4A, if the control wire is pulled distally after the jawshave been closed, and the force on the control wire 36 exceeds thepredetermined limit of spring 38, the proximal coupling 38 a which isfixedly coupled to the control member 36 will be moved distally againstthe cap 38 b and the force limiting cup 38 c. The force limiting cup, inturn will move distally, compressing the spring 38 against the nut 38 dwhich is fixed in place because of its linkage to lever 22 which islocked.

In either case, when the lever 22 is released, the spring 38 willdecompress by linkage 44 causing the nut 38 d to move distally until itabuts the distal coupling 38 e (which is coupled to the control member36). The distal movement of the nut 38 d causes distal movement of thedistal coupling 38 e which is coupled to the control member 36 causingthe control member 36 to move distally.

According to the presently preferred embodiment, the spring is alwayscompressed when the lever 22 is moved to the locked position.

To permit rotation of the control member 36, the knob 24 is coupled tothe control member 36 via a spline 40 mounted in a shaft bearing 24 aheld by a clamp 24 b. The proximal end of the control member 36 is bentinto a shepherd's crook 36 a which slidably engages the spline 40coupled to the knob 24. A shepherd's crook is illustrated in FIG. 29.Rotation of the knob 24 thus causes rotation of the control member 36.

It should be noted that in the force limiting mechanism 37, the distalcoupling 38 e and the proximal coupling 38 a are assembled in such a wayas to allow clearance with the rest of the force limiting assembly 37.This clearance allows for ease of rotation since friction created by thepreloaded spring 38 is not translated into torsional resistance.

FIG. 4B shows a first alternate embodiment of a force limiting mechanism137. Here, the coil 112 is provided with a proximal bushing 113. Themanual actuator or handle 118 is provided with a recess 119 which isdimensioned to receive the bushing 113, a washer/spacer 115, and acompression spring 138 therebetween. Those skilled in the art willappreciate that if, during closing of the jaws, an obstacle prevents thejaws from closing fully, the proximal force applied to the controlmember 136 will be applied to the distal clevis 182, the coil 112, andthe handle 118. The handle will exert an equal and opposite force in thedistal direction against the washer/spacer 115. As a result, when thespring force of the compression spring 138 is exceeded, the proximal endof the coil will move the bushing 113 against the spring 138.

Still referring to FIGS. 1-6, and particularly FIG. 4, the crank 26 iscoupled to a transmission 46 which is coupled to a second control member48. More particularly, the transmission includes an input spur gear 47which is coupled to the crank, a step-up spur gear 49 coupled to theinput spur gear, and a crown gear 50 which is coupled to the step-upspur gear. The crown gear engages a pinion 52 coupled to a cylinder 54having a keyed interior which engages the second control member 48 whichis provided with a shepherd's crook 48 a (also as illustrated in FIG.29) at or near its proximal end. The cylinder 54 is mounted on twobearings 55, 57 which are held by clamps 55 a, 57 a. The second controlmember 48 (as discussed in detail below with reference to FIGS. 8-11) isthreaded along a distal portion thereof. From the discussion whichfollows, it will be appreciated that the length of the cylinder 54 issufficient to allow distal movement of the second control member 48until all of the clips have been dispensed. According to the presentlypreferred embodiment, the control member 48 is made from 17-7 PHstainless steel wire.

According to the presently preferred embodiment, an energy storingflywheel 56 is coupled to the cylinder 54. Alternatively, the flywheeland cylinder could be a single molded part. The flywheel smoothes theoperation of the crank which would otherwise require the application ofincreasing force through its rotation, as in the beginning of itsrotation, the control member is causing a clip to be advanced, whereasat the end of its rotation, the control member is causing the clip to beformed by pushing it against an anvil in the end effectors (as discussedin more detail below). Those skilled in the art will appreciate that inorder to be effective, the flywheel is preferably provided with arelatively large rotational mass for energy storage. When the flywheelis spun (rotated) by rotation of the crank, a certain amount of energyis invested which increases the kinetic energy (mass×velocity) of theflywheel. Some of this energy is lost over time to friction; however,some of the energy used to spin the flywheel is stored in the form ofkinetic energy. Later, it is possible to retrieve this energy throughdirect mechanical translation. In the case of the present invention,when the crank 26 is first rotated, the control member 48 offers littleresistance (as the clips are moving forward easily) and most of theenergy applied to the crank is used to put the flywheel 56 in rotation.Near the end of the crank's rotation, torsional resistance is built upby the control member 48 because it is near the end of the cycle wherethe clip is being bent into its final shape. At this point, the kineticenergy in the flywheel is released and eases the remainder of the crankcycle. Preferably, according to the invention, the flywheel 56 is chosenso that the force which is applied to the crank 26 is substantially even(e.g., does not change by more than 25%) over the entire movement of thecrank 26 necessary to dispense a single clip.

As seen best in FIGS. 5 and 6, the crank 26 is provided with a detentlock 58 which must be released before the crank 26 can be turned andwhich automatically locks the crank 26 after one rotation. Preferably,the crank 26 is also provided with a ratchet mechanism (not shown) whichprevents it from being rotated backwards. The crank is also preferablyprovided with a lock (not shown) which prevents it from being turneduntil the jaws are closed. The crank may also be provided with arevolution counter (not shown) which can be coupled to the input spurgear and which counts the number of times the crank has been rotated andthus indicates the number of clips which have been dispensed. Therevolution counter may also be used to prevent the crank from rotatingafter all of the clips have been dispensed. Ideally, the crank is alsoprovided with a lockout mechanism which prevents it from being rotatedtwice without opening and closing the jaws between rotations of thecrank.

According to the embodiment illustrated in FIGS. 5 and 6, the crank 26has a plurality of spaced apart peripheral finger grips 26 a and aknurled outer periphery 26 b. The crank handle 26 c is optionallyremovable so that the crank can be rotated like a knob if desired. Thedetent lock 58 includes a push button 58 a having a flange 58 b, a lockpin 58 c having a flange 58 d and a spring 58 e. The lock pin 58 c isdisposed in a stepped bore 58 f and is biased by the spring 58 e intothe stepped bore 26 d in the crank 26. When the button 58 a is pressed,the lock pin 58 c is moved against the spring 58 e and out of the bore26 d, freeing the crank to rotate.

According to an exemplary embodiment, the transmission causes the secondcontrol member to be rotated 58.1875 revolutions when the crank isturned one revolution. The pitch of the threads on the control memberresult in the control member advancing 0.285 inches when the crank isturned one revolution. The gears and the thread pitch are selected for aparticular clip length. According to the presently preferred embodiment,it is only necessary to change the crown gear (by increasing ordecreasing the number of teeth) to accommodate clips of differentlength.

As illustrated in FIGS. 1-4 and 4 a, the distal end of the manualactuator 18 has a pair of vertical slots 15 which capture a coilconnector (not shown) that is attached to the proximal end of the coil.

The Control Members

Referring now to FIGS. 7-10, the control members 36, 48 extend through aflexible coil 12 coupled to the distal end of the manual actuator 18.According to the invention, the coil 12 has two parts: a proximal part12 a and a distal part 12 b which are coupled to each other by a rigidmember 60. The rigid member 60 is substantially cylindrical having acenter portion 60-1 of larger diameter than the end portions 60-2, 60-3.The end portions 60-2, 60-3 are dimensioned to fit inside the coils 12a, 12 b and the central portion 60-1 is dimensioned to have an outerdiameter substantially the same as the outer diameter of the coils 12 a,12 b. The rigid member 60 has four bores 60 a-60 d. One of the bores, 60d, is threaded and engages the threaded portion of the second controlmember 48. Because the rigid member 60 is fixed relative to the coils 12a, 12 b, it will be appreciated that this threaded engagement causes thesecond control member 48 to move distally through the rigid member 60when it is rotated by the crank 26 (FIG. 2).

Two of the other holes, 60 a and 60 b, in the rigid member 60 allow thepassage of a pair of pull wires 62, 64 which are described in moredetail below with reference to FIGS. 16 and 17. The proximal ends of thepull wires are coupled to a joiner 66 which has four bores 66 a-66 d.One pull wire is coupled to bore 66 a and the other is coupled to bore66 b. The first control member 36 extends through and is coupled to thebore 66 c, and the threaded control member 48 freely passes through thebore 66 d. In this manner, longitudinal movement of the first controlmember 36 causes longitudinal movement of the pull wires 62, 64. Theportion 36 a of the control member 36 which extends through the joiner66 extends into the bore 60 c of the rigid member 60. The length of thisportion 36 a is sufficient to engage the bore 60 c throughout the rangeof movement of the control member 36. In this manner, rotation of thecontrol member 36 with the knob 24 (FIG. 1) causes rotation of the rigidmember 60 which causes rotation of the distal portion 12 b of the coil12 which results in rotation of the jaws 20 and the store of clips aboutthe longitudinal axis of the coil.

As seen best in FIG. 8, the control members 36 and 48 are protected by adual lumen flexible sheath 68 inside the proximal portion 12 a of thecoil 12. The sheath 68 reduces friction between the control members andthe interior of the coil. The sheath 68 also prevents buckling orkinking of the control members. It should also be noted that afriction-reducing sheath is preferably provided along the entireexterior surface of the coil to reduce friction between the coil and thelumen of the endoscope through which it is delivered and to protect thelumen of the endoscope from damage.

According to a presently preferred embodiment, both control members havesmaller diameters in their distal portions to add flexibility and largerdiameters in the proximal portions to optimize torque transmission.

The Pusher

Turning now to FIGS. 11-13, the distal end of the threaded controlmember 48 is coupled to a clip pusher 70. As seen best in FIG. 12, thepusher 70 is a generally rectilinear member having an off-axis bore 70 aintersected by a notch 70 b. A pair of inwardly curved distallyextending fingers 70 c, 70 d are separated from a distal mouth 70 e byshoulders 70 f, 70 g. As seen best in FIG. 11, the distal end of thethreaded control member 48 extends through the bore 70 a and is coupledto a cylinder 72 which is captured in the notch 70 b. The cylinder 72may be crimped or welded to the control member 48. The coupling of thepusher and the control member is such that the control member can freelyrotate relative to the pusher. As seen best in FIG. 11, the distal end48 b of the control member 48 is sharpened to a point and the distal endof the throughbore 70 a is provided with a conical wall 70 h. The apexangle of the conical wall 70 h is larger than the apex angle of thepoint 48 b. From the foregoing, those skilled in the art will appreciatethat when the control member 48 is rotated, it moves distally, pushingthe pusher distally. It will also be appreciated that the frictionalengagement of the control member 48 with the pusher 70 is limited to thesmall area of engagement of the point 48 b with the apex of the cone 70h.

As seen best in FIG. 13, the clip pusher 70 is arranged adjacent to theproximally closest clip 74 in the store of clips 76 which are axiallyarranged one after the other proximal to the jaw assembly 20. When thecontrol member 48 is translated distally, the store of clips 76 is moveddistally until the ultimate clip 78 (the one at the distal end of thestore) enters the closed jaws and is applied to tissue through thebending of its ends by the interior anvils of the jaws. FIG. 13 showsthe jaws open after the clip 78 was applied.

As seen best in FIG. 11, the clip 74 (which is identical to all of theother clips) has a proximal tail 74 a which is engaged by the mouth 70 eand shoulders 70 f, 70 g of the pusher 70. The fingers 70 c and 70 dconstrain the clip from vertical movement and allow the pusher tolightly grab the clip, which facilitates clip loading during assembly.Additional details of the clip may be appreciated upon review ofpreviously incorporated U.S. Ser. No. 10/867,412.

Those skilled in the art will appreciate that the arrangement of threadscould be changed while still achieving the same or similar results. Forexample, rather than arranging the threaded control member to advancedistally, threads could be supplied on the pusher with the threadedcontrol member being translationally stationary. In this arrangement,rotation of the threaded control member causes the pusher to betranslated along the control member.

The Garage

As seen best in FIGS. 13 and 16, the store of clips 76 is housed in agarage 80 inside the distal portion 12 b of the coil 12 proximal to thejaw assembly 20. Details of the garage 80 are seen in FIGS. 14-17. Thegarage 80 generally comprises a plurality of parallel side walls 80a-801 and pair of distally extending fingers 80 m, 80 n which areorthogonal to the side walls. Each side wall has a plurality ofoutwardly directed spacers, e.g. 80 c-1, 80 c-2, 80 c-3, 80 c-4. Thesespacers engage the interior of the coil and assure space between thecoil and the garage for the passage of the pull wires 62, 64 (see FIG.16). Formation of the outwardly directed spacers results in narrowstrips, e.g. 80 ab, 80 bc, 80 cd, etc., which add flexibility to thegarage. The flexibility at the distal end of the instrument can beimportant in cases where the endoscope is retroflexed. As seen best inFIG. 16, when the clips are arranged in the garage, the abutment of oneclip against another lies in this narrowed region. Thus the clips canflex at their abutment.

As seen best in FIG. 15, the distally extending fingers 80 m, 80 n eachhave an outwardly extending distal lip 80 m-1, 80 n-1 and an inwardlyextending proximal stop 80 m 2, 80 n-2. The fingers 80 m, 80 n helporient the garage relative to the clevis. The distal lips help thegarage engage the clevis as described below and the proximal stop'sprevent unwanted movement of the penultimate clip as described below.Opposite pairs of parallel fingers 80 p and 80 q are arranged in spacedapart planes orthogonal to the planes of the fingers 80 m, 80 n. Thesefingers 80 p, 80 q extend from a proximal collar 80 r and engage theclevis as seen best in FIG. 17, described in detail below.

According to the presently preferred embodiment, the garage is made froma single piece of stamped and folded stainless steel.

Unlike our earlier clip appliers, there is no need to chain the clipstogether so that they can be pulled back. There is also no need to pullany of the clips back at any time.

The Jaw Assembly

FIGS. 17-27 illustrate details of the jaw assembly 20 which includes aclevis 82 and a pair of jaws 84, 86. The jaws are hermaphroditic matingjaws, i.e. the jaws are identical and arranged to mate with each other.Each has a proximal tang 84 a, 86 a, a plurality of side teeth 84 b, 86b, which are offset one half pitch from each other on opposite sides ofthe longitudinal axis of the jaw, a distal tooth 84 c, 86 c, and amounting hole 84 d, 86 d. The jaws are coupled to the clevis via theirmounting holes. As seen best in FIG. 27, the clevis 82 has two off-axisbosses 82 a, 82 b upon which the jaws are mounted and held in place byrivets. The distal ends of the pull wires 62, 64 are bent into dogs-legswhich are coupled to respective tangs 84 a, 86 a of the jaws. It willthus be appreciated that distal movement of the pull wires will causethe jaws to open as shown in FIGS. 18 and 19 and proximal movement ofthe pull wires will cause the jaws to close as shown in FIGS. 20 and 21.The use of offset bosses increases the mechanical advantage of the jaws.The clevis also is provided with a pair of stops 82 e, 82 f (best seenin FIG. 26) which engage ears 84 a-1, 86 a-1 on the tangs of the jawsand which allow the jaws to be deflected 45-60 degrees off axis whenthey are closed and which also allows for an approximately ten degreeover-rotation of the jaws. This allows the closed jaws to traverse atortuous path through the lumen of an endoscope.

As seen best in FIG. 19, the proximal tang and the distal tooth of eachjaw lie on opposite sides of the longitudinal axis of the jaw assembly.This arrangement provides stability to the end effector arrangement. Inparticular, there is a certain amount of clearance between the jaws andthe clevis so that the jaws can rotate easily open and closed. Thisclearance may allow the jaws to rock horizontally on the clevis creatingthe possibility of jaw misalignment. In the illustrated embodiment, thejaws are forced toward each other horizontally as they are being closedrather than away from each other. This is because the forming anvils actin opposition to the horizontal moments generated by the pull wires.

The interior surfaces of the distal teeth are forming anvils which causethe two tines of the clip to be bent through approximately 90-180° asshown in FIGS. 20 and 23. In particular, as seen in FIGS. 19 and 21, thedistal teeth define two curvature paths, parallel to each other. Thisallows the two tines of the clip to be bent into parallel semi-circles.The distal teeth also function as a tissue fixation point indicator asthe point(s) where the teeth meet are adjacent the location where thetines of the clips pierce the tissue.

As seen best in FIG. 23, after the distal-most (ultimate) clip 78 hasbeen applied, the adjacent or penultimate clip 78 a is held by the stops80 m-2 and 80 n-2 in the garage 80 and the tines of the clip 78 aembrace the tail of the clip 78. When the jaws are opened, the jawassembly can be moved away from the ultimate clip 78 without releasingthe penultimate clip 78 a. As seen best in FIG. 18, with the jaws open,the tines of the penultimate clip 78 a are shielded by distal fins 82 c,82 d of the clevis 82. However, if the clevis is dimensioneddifferently, these fins 82 c, 82 d are not necessary because the tinesof the clip will not extend out of the clevis until it is being applied.Other illustrations of the clevis (e.g. FIG. 26) do not show the fins.

As shown in FIG. 17, the garage mates with the clevis in three places inorder to secure the garage relative to the clevis. A distal mating isobtained with distal lips 80 m-1 and 80 n-1 engaging lips 82 e and 82 fof clevis 82 (shown best in FIG. 22). A proximal mating is obtained withfingers 80 p and 80 q engaging lateral recesses or bores 82 g, 82 h. Thethird mating is provided by sandwiching the proximal collar 80 r betweenthe clevis core and the distal end of the coil.

Alternate Embodiment, Self-Pushing Clip

Referring now to FIGS. 28-30, alternate embodiments of a clip 301 and aclip advancement mechanism are shown. The clip 301 has substantially thesame configuration as the clip described above except that it has athreaded hole 301 a in its proximal end. FIG. 28 shows a plurality ofclips 301-304 threadably mounted on the threaded end 148 a of rotatablecontrol member 148. The control member 148 is similar to the controlmember 48 described above except that it is mounted in a way that itdoes not translate relative to the coil or the actuator. In particular,control member 148 is mounted in a thrust collar 310 set in a thrustbearing 312 which is located between the proximal and distal coils (notshown). When the control member 148 is rotated, the clips 301-304 whichcannot rotate because of the garage (not shown) are translated throughthe garage because of their threaded engagement with the control member.

The Presently Preferred Manual Actuator

FIGS. 30-37 illustrate the presently preferred manual actuator 418.Similar reference numerals, increased by 400, refer to similar parts tothe manual actuator 18 of FIGS. 1-6. The manual actuator 418 includes alever 422, a knob 424, and a crank 426. According to a first aspect ofthis embodiment, a second crank 426′ is provided on the opposite side ofthe actuator. As seen best in FIGS. 30 and 32, the “cranks” 426, 426′are knurled and do not have crank handles like the crank 26. Like theactuator 18, and as seen in FIGS. 31-33, the actuator 418 is providedwith a finger grip 428 and a lever 422 having a thumb grip 430. Engaginghooks 432, 434 allow the lever to be releasably locked in the closedposition as shown in FIG. 32.

As seen best in FIG. 32, a polygonal crank shaft 500 extendstransversely through the actuator 418 and is engaged on opposite ends bythe cranks 426, 426′. The crank shaft 500 is surrounded by a cylindricalstructure 502, 504 on opposite sides of the actuator 418. According to asecond aspect of this embodiment, one of the cylinder structures 504 isprovided with a plurality of ratchet teeth 506, and as seen in FIG. 33,the crank 426′ has a peripheral post 508 upon which a ratchet pawl 510is mounted. Those skilled in the art will appreciate that the ratchetand pawl prevent both cranks 426, 426′ from being rotated backward,i.e., clockwise in the illustrated embodiment.

According to a third aspect of this embodiment, as seen best in FIGS. 34and 35, the transmission 446 is coupled to a counter gear 512. In thisembodiment, the transmission gears are arranged slightly differentlythan in the embodiment of FIGS. 1-6. In particular, the crank shaft 500is coupled to a small hub gear 514 which engages the counter gear 512 asshown in FIG. 35. The crank shaft is also coupled to an input spur gear447 which drives a step up spur gear 449 which is flipped over ascompared to the gear 49 shown in FIG. 4. The spur gear 449 drives thecrown gear 450 which is coupled to the pinion 452. The pinion 452 iscoupled to the cylinder 454 which is turn is coupled to the flywheel456.

The counter gear 512 is provided with indicia 516, preferably on bothsides, and a standing rib 518. The body of the actuator 418 is providedwith at least one, but preferably two windows 520, 522 (see FIGS. 31-33,36 and 37) through which the indicia 516 of the counter gear can beviewed (one at a time). The illustrated counter is for use with a storeof five clips. When the garage is full, the portion of the counterbetween the standing rib 518 and the numeral “4” is visible through thewindow. In order to accommodate space for the standing rib, the numberof teeth on the counter gear is chosen so that one rotation of the hubgear causes slightly less than ⅕ rotation of the counter gear. As clipsare dispensed, the counter gear rotates clockwise counting down thenumber of clips remaining. When there are “0” clips remaining, the “0”indicia is visible through the window. In addition, when in thisposition, the standing rib 518 abuts a structure inside the actuator,e.g. a wall of the window opening. This prevents the counter gear andthe cranks from advancing further. Preferably, the counter gear 512 isprovided with an index hole 524 which is used to properly orient thegear during assembly.

Those skilled in the art will appreciate that means other than thestanding rib 518 could be used to stop rotation. For example, thethreads on the control member 48 can be arranged to run out upondispensing the last clip. Alternatively, a bump can be provided on thecontrol member 48 at a location to be stopped by engaging the rigidmember 60 upon dispensing the last clip. Still another alternative is toarrange the pusher 70 to engage and lock on the detent fingers 80 m, 80n after the last clip has been fired. The purpose of the stop is toprevent the pusher from entering the jaws and to indicate that all ofthe clips have been used.

According to a fourth aspect of this embodiment and as illustrated inFIGS. 36 and 37, the crank detent lock 458 is engaged by the lever 422such that the crank can only be turned when the jaws are closed. Inparticular, the floor of the previously identified cylindrical structure502 is provided with a ramp 526 which rises to a step 528. The crank 426and/or the crank shaft 500 are/is coupled to a leaf spring 530 whichextends generally radially out from the axis of the crank shaft andterminates with an upturned lip 532. FIGS. 36 and 37 illustrate thecrank/crank shaft in the locked position with the leaf spring 530 lyingadjacent the step 528. If the crank were operated to dispense a clip,rotation of the crank would be stopped by the leaf spring 530 hittingthe step 528.

The lever 422 has a tongue 534 with a lifting ramp 536 at its end. Amouth 538 opens into the cylindrical structure 502 adjacent to the step528. The tongue 534 is arranged so that it enters the mouth 538 when thelever 422 is moved to the closed position, closing the jaws. When thetongue 534 enters the mouth 538, the lifting ramp 536 engages theupturned lip 532 and raises the leaf spring 530 above the step 528. Inthis position, the leaf spring and the step no longer impede rotation ofthe cranks, and a clip may be dispensed. Rotation of the crank moves theleaf spring down the ramp 526 onto the floor of the cylindricalstructure where it is free to move around in a complete rotation. Thetongue 534 is provided with a lower recess 540 which allows the leafspring 530 to pass under it at the end of a single rotation of thecrank, at which point the spring will once again abut the step 528. Thetongue 534 is resilient enough so that the recess 540 can pass over theupturned lip 532 when the lever 422 is moved back to open the jaws.Thus, the crank will move exactly one rotation after the jaws are closedand will not move again until the jaws are opened and then closed again.

Alternate Embodiments of Force Limiting Springs

FIGS. 38-40 illustrate a first alternate embodiment of a force limitingspring in a manual actuator 600 which in other respects is substantiallythe same as the actuator described above. The actuator 600 has a thumblever 602 which is coupled to a linkage 604. The distal end of thelinkage 604 engages the distal end of a spring 606. A washer 608 islocated adjacent the proximal end of the spring 606 and a “shuttle” 610is located proximal of the washer 608 and abuts a stop wall 611 on thelinkage 604. The control member 612 extends through the linkage 604, thespring 606, the washer 608, and is coupled to the shuttle 610. Theshuttle 610 is composed of two identical pieces illustrated in FIG. 40.Each piece 610 is generally semi-cylindrical, has a pair of locking nubs610 a, 610 b and a pair of nub-receiving sockets 610 c, 610 d. Theinterior of the piece 610 has an off center wire engaging tongue 610 eand each end is provided with an axial half bore 610 f, 610 g. From theforegoing, those skilled in the art will appreciate that when a controlwire is placed between the two pieces of the shuttle and they arepressed together, the control wire will be bent into an S shape by thetwo tongues 610 e and the shuttle will be fixed relative to the controlwire.

With the foregoing in mind, it will also be appreciated that when thelever 602 is moved from the open position (FIG. 39) toward the closedposition shown in FIG. 38, the linkage 604 moves the spring 606 andwasher 608 proximally against the shuttle 610 pulling the control wire612 proximally until the control wire can be pulled no more, or until apredetermined tension is placed on the wire. At that point, furtherclosure of lever 602 continues to move the linkage 604 and spring 606proximally. However, because the wire 612, washer 608, and shuttle 610will not move (or because the spring constant is less than the tensionon the wire), the spring 606 begins to compress between the linkage 604and the washer 608 and remains compressed when the lever is locked. Theamount of compression will depend on the tortuosity of the path of thecontrol wire. According to the presently preferred embodiment, there isalways some spring compression when the lever is locked as shown in FIG.38. When the lever 602 is released, at first, the linkage 604 will movedistally relative to the washer and shuttle and the spring will expand.Eventually, the stop wall 611 on the linkage 604 will reach the shuttle610 and push the shuttle distally, thereby causing the control wire 612to move distally.

It will be appreciated by those skilled in the art that the function ofthe washer 608 is to provide a positive interference between the spring606 and the shuttle 610. One manner of providing the positiveinterference is to partially close the end of spring 606 by bending theend of the spring 606 into an “e” shape. Alternatively, the end of thespring wire can be flattened and broadened to interfere with theshuttle. It will also be appreciated by those skilled in the art thatinstead of providing a stop wall 611 on the linkage 604 for the shuttle610, the lever 602 can be arranged to directly push the shuttle (andhence wire 612) distally upon the release of the lever from the closedposition.

FIGS. 41-43 illustrate a second alternate embodiment of a force limitingspring in a manual actuator 700 which in other respects is substantiallythe same as the actuator described above. The actuator 700 has a thumblever 702 which is formed in two parts 702 a, 702 b coupled to eachother by a torsion spring 706. As seen best in FIG. 42, the upper part702 b of the lever 702 has a socket 702 c for receiving a ball 710coupled to the control wire (not shown) and two spaced apart legs 702 d,702 e. The lower part 702 a of the lever has an upper finger 702 f whichextends between the legs 702 d, 702 e. The torsion spring 706 is mountedon a pivot axle 703 which extends through the upper finger 702 f and thelegs 702 d, 702 e. The back of the spring 706 a engages the back of thefinger 702 f and the front of the spring 706 b engages the upper part ofthe lever 702 b. The ball is made of two identical pieces illustrated inFIG. 43. The piece is generally hemispherical but is similar to thepreviously described shuttle in that it has a pair of locking nubs 710a, 710 b and a pair of nub-receiving sockets 710 c, 710 d. The interiorof the piece 710 has an off center wire engaging tongue 710 e and a pairof diametrically opposed half bores 710 f, 710 g are provided coaxialwith the tongue 710 e. From the foregoing, those skilled in the art willappreciate that when a control wire is placed between the two pieces ofthe ball and they are pressed together, the control wire will be bentinto an S shape by the two tongues 710 e and the ball will be fixedrelative to the control wire.

With the foregoing in mind, it will be appreciated that when the lever702 is moved from an open position toward the closed position shown inFIG. 41, the upper part 702 b of the lever and the control wire (notshown) are moved proximally until the control wire cannot be pulledfurther. At this point, the upper part 702 b of the lever remainsstationary. However, in order to reach a fully closed lever position,the lower lever part 702 a can continue to rotate about the pivot axle703 and cause the finger 702 f to exert force against the back part 706a of the spring 706, thereby causing the spring front part 706 b tospread away from spring back part 706 a and top lever part 702 b. Whenthe lever is eventually released from its fully closed position, atfirst the force of finger 702 f against the spring is released and theball 710 and wire will not move. Eventually, when spring front part 706b hits the top lever part 702 b, the entire lever, the ball 710 and thecontrol wire are moved distally.

Pre-loaded Clip Ejector

In the presently preferred embodiment, at least a distal portion of theflexible coil (in this case the distal coil 12 b) is pre-loaded toprovide sufficient columnar stiffness. When the jaws 84, 86 are closed,the pull wire(s) increase the load between the clevis and the nut. Afterthe clip is deployed, the pull wires are actuated distally to open thejaws. The force of the compressed clip train, and if necessary, theforce from the pull wires is sufficient to overcome the pre-load of thedistal coil so that the jaws and clevis move away from the tines of theclip, which have been compressed against the forming anvils of the jaws.An alternate embodiment of this concept provides oblong holes in thejaws for attachment to the bosses on the clevis. When the jaws areclosed, the pull wires move the jaws proximally with respect to theclevis. When the pull wires are released from tension and actuateddistally, the jaws are also able to move distally with respect to theclevis to release the compressive load on the tines of the clip.

According to an alternative embodiment, the distal coil 12 b ispre-loaded to spring distally. When the jaws 84, 86 are closed, the pullwire(s) 62 pull against the distal coil, shortening the distal coilagainst its pre-load. After the clip is dispensed, the jaws are opened.When the jaws are opened, the pre-load on the distal coil causes theclevis 82, jaws 84, 86, and garage 80 all to move a slight distancedistally. At the same time, the clips do not move, as they are freelydisposed in the garage which is moving over them. This action has theeffect of separating the distal anvils on the jaws from the tines on theformed clip, thereby easing the opening of the jaws.

The pre-loading of the distal coil provides the coil with sufficientcolumnar strength to allow for tangential bites, prevents bucklingduring jaw closure, and provides reaction force to overcome frictionalforces as the jaws open.

Alternate Jaw Embodiment

FIGS. 44 and 45 illustrate an alternate embodiment of jaws 184, 186which are substantially the same as the jaws 84, 86 but for theirmounting holes 184 d, 186 d. In this embodiment, the mounting holes 184d, 186 d are not circular. They are oblate or “slotted”. This allows thejaws to slide distally and proximally as they are opened and closed.Thus, when the jaws are closed as shown in FIG. 44, they are pulledproximally. In this position, the clip is fired into the closed jawswhich act as forming anvils as described above. When the jaws are openedas shown in FIG. 45, they slide distally away from the formed clipseparating the distal anvils on the jaws from the tines on the formedclip, thereby easing the opening of the jaws.

There have been described and illustrated herein several embodiments ofa flexible endoscopic clip applier. While particular embodiments of theinvention have been described, it is not intended that the invention belimited thereto, as it is intended that the invention be as broad inscope as the art will allow and that the specification be read likewise.Thus, while the coils of the invention have been described as beingformed from flat stock, it will be appreciated that the stock can be ofcircular or other cross-section. Also, while particular materials havebeen described as preferred in making various of the elements of theinvention, it will be appreciated that other materials can be utilized.Further, while the invention has been described as utilizing a geararrangement which provides a specific number of turns to a wire controlelement for advancing the clips, it will be appreciated that other geararrangements which provide the same or different numbers of turns of thewire control element can be provided. Further, while the invention hasbeen disclosed in conjunction with two different kinds of end effectors,i.e. the jaws and the clip pusher, other components of the invention maybe used with different end effectors. It will therefore be appreciatedby those skilled in the art that yet other modifications could be madeto the provided invention without deviating from its spirit and scope asclaimed.

1. An endoscopic surgical instrument, comprising: a flexible tube havinga proximal end and a distal end; a threaded member coupled to saidflexible tube toward said distal end of said flexible tube; an endeffector coupled to or housed within said distal end of said flexibletube; an actuator coupled to said proximal end of said flexible tube; athreaded control member extending through said flexible tube andengaging said threaded member, said threaded control member coupled tosaid end effector and to said actuator, wherein said actuator rotatessaid threaded control member and thereby translates said threadedcontrol member relative to said threaded member to operate said endeffector, said flexible tube comprises a first flexible tube having aproximal end and a distal end, and a second flexible tube having aproximal end and a distal end, said threaded member being coupledbetween said distal end of said first flexible tube and proximal end ofsaid second flexible tube, said end effector coupled to or housed withinsaid distal end of said second flexible tube, and said actuator coupledto said proximal end of said first flexible tube.
 2. The instrumentaccording to claim 1, further comprising: a torque providing membercoupled to said actuator and extending through said first flexible tube,said threaded member having an off axis bore which receives said torqueproviding member, whereby rotation of said torque providing membercauses rotation of said threaded member and said second flexible tube.3. An endoscopic surgical instrument, comprising: a flexible tube havinga proximal end and a distal end; a connecting member coupled to saidflexible tube toward said distal end of said flexible tube, saidconnecting member having an axially offset bore; an end effector coupledto or housed within said distal end of said flexible tube; an actuatorcoupled to said proximal end of said flexible tube; a torque providingcontrol member coupled to said actuator and extending through saidflexible tube into said axially offset bore; at least one control wirecoupled to said end effector and said torque providing control member,wherein rotation of said torque providing control member causes rotationof said end effector about a first axis and translation of said torqueproviding control member causes rotation of said end effector about asecond axis, said flexible tube comprises a first flexible tube having aproximal end and a distal end, and a second flexible tube having aproximal end and a distal end, said connecting member being coupledbetween said distal end of said first flexible tube and proximal end ofsaid second flexible tube, said end effector coupled to or housed withinsaid distal end of said second flexible tube, and said actuator coupledto said proximal end of said first flexible tube.